The present invention relates to a water dispersion type water and oil repellent composition which is excellent in stability during storage and which can impart excellent water and oil repellency to an object to be treated, and an object treated with it.
It has been conventionally known that an aqueous dispersion having dispersed in an aqueous medium of a polymer containing polymerization units having polymerizable monomers having Rf groups or a compound containing Rf groups treats with fibers and imparts water and oil repellency on their surface. (JP-B-47-40467). It has been known that among various water and oil repellent compositions, a copolymer containing as the main components polymerized units of a polymerizable monomer having an Rf group and a polymerizable monomer having a stearyl group (such as stearyl acrylate) provides more flexible touch and hand than a water and oil repellent composition which employs another polymerizable monomer (such as vinyl chloride).
However, of a conventional water and oil repellent composition, the difference between a specific gravity of stearyl (meth)acrylate (0.86 g/ml) and a specific gravity of a polymerizable monomer having an Rf group (1.4-1.6 g/ml) is large, and thus it tends to be difficult to uniformly disperse these two polymerizable monomers in a polymerization medium, in a case where a copolymer is obtained by e.g. emulsion polymerization or suspension polymerization, and it may be necessary to employ a specific reactor or agitator or a pre-emulsification apparatus such as a high pressure emulsifier.
Further, when the polymerization is carried out without mixing stearyl acrylate with a polymerizable monomer having an Rf group uniformly, there will be the fluctuation of the composition of the copolymer, thus decrease the water repellent performance. Further, a difference of specific gravity of dispersed compounds may cause instability of the water and oil repellent composition during storage and decrease chemical or mechanical stability of a processing bath.
Under these circumstances, it is an object of the present invention to improve uniform mixing properties of stearyl (meth)acrylate with a polymerizable monomer having an Rf group and to achieve uniformalization of a copolymer composition, and to achieve improvement of storage stability of a water dispersion type water and oil repellent composition containing the above copolymer, improvement of initial water and oil repellency of an object treated with it, and improvement of a processing bath stability.
The present invention has been made to solve the above problems. The present inventors have conducted studies on uniform mixing of stearyl (meth)acrylate with a polymerizable monomer containing an Rf group, and as a result, have found that the concentration of impurities in stearyl (meth)acrylate as a material greatly influences over uniform mixing properties of stearyl (meth)acrylate with a polymerizable monomer having an R group. As a result of further extensive studies, it has been found that the uniform mixing properties will be excellent when the purity of stearyl (meth)acrylate as a material is higher than 91 mass %. Particularly, it has been found that the uniform mixing properties are very excellent when the total amount of stearyl alcohol, a reaction product of stearyl (meth)acrylate and (meth)acrylic acid (impurity X), and a reaction product of stearyl (meth)acrylate and stearyl alcohol (impurity Y) is at most 9 mass % in stearyl (meth)acrylate as a material, and accomplished the present invention.
Namely, the present invention provides a water dispersion type water and oil repellent composition containing a copolymer (A) which has polymerized units based on a polymerizable monomer having an Rf group and polymerized units based on stearyl (meth)acrylate, and which is produced by using a material having a purity of stearyl (meth)acrylate higher than 91 mass %, wherein the ratio of particles having an average particle diameter of from 30 to 150 nm is at least 80% of the total number of particles of the copolymer (A) in a dispersion medium.
Further, the present invention provides the above water dispersion type water and oil repellent composition, wherein the stearyl (meth)acrylate as the material contains an impurity (B) which is at least one member selected from the group consisting of stearyl alcohol, a reaction product of stearyl (meth)acrylate and (meth)acrylic acid (impurity X), and a reaction product of stearyl (meth)acrylate and stearyl alcohol (impurity Y).
Further, the present invention provides the above water dispersion type water and oil repellent composition, wherein the content of stearyl alcohol in stearyl (meth)acrylate as the material is at most 3 mass %.
Further, the present invention provides the above water dispersion type water and oil repellent composition, wherein the content of the impurity X in stearyl (meth)acrylate as the material is at most 2 mass %.
Further, the present invention provides the above water dispersion type water and oil repellent composition, wherein the content of the impurity Y in stearyl (meth)acrylate as the material is at most 4 mass %.
Further, the present invention provides the above water dispersion type water and oil repellent composition, wherein the polymerizable monomer having a polyfluoroalkyl group is a (meth)acrylate having a perfluoroalkyl group of the carbon number of from 4 to 20.
Further, the present invention provides an object treated with any one of the above water dispersion type water and oil repellent composition.
Now, the present invention will be described in detail with reference to the preferred embodiments.
In this specification, an acrylate and a methacrylate will generally be represented by (meth)acrylate, acrylic acid and methacrylic acid will generally be represented by (meth)acrylic acid, and acrylamide and methacrylamide will generally be represented by (meth)acrylamide.
The Rf group is a group having at least two hydrogen atoms in an alkyl group substituted by fluorine atoms. The carbon number of the Rf group is preferably from 2 to 20, particularly preferably from 6 to 16. The Rf group may be of a linear structure or a branched structure, and a linear structure is particularly preferred. In the case of a branched structure, it is preferred that the branched portion is located at a terminal portion of the Rf group, and has a short chain of from 1 to 4 carbon atoms.
The Rf group may contain halogen atoms other than fluorine atoms. As such another halogen atom, a chlorine atom is preferred. Further, an etheric oxygen atom or a thioetheric sulfur atom may be inserted between a carbonxe2x80x94carbon bond in the Rf group. The structure of the terminal portion of the Rf group may, for example, be xe2x80x94CF2CF3, xe2x80x94CF(CF3)2, xe2x80x94CF2H, xe2x80x94CFH2 or xe2x80x94CF2Cl, and xe2x80x94CF2CF3 is preferred.
The number of fluorine atoms in the Rf group is preferably at least 60%, particularly preferably at least 80%, when represented by [(the number of fluorine atoms in the Rf group)/(the number of hydrogen atoms contained in an alkyl group corresponding to the same carbon number as the Rf group)]xc3x97100(%).
When the Rf group is preferably a group having all the hydrogen atoms in an alkyl group substituted by fluorine atoms (i.e. perfluoroalkyl group) or a group having a perfluoroalkyl group at a terminal portion.
The carbon number of the perfluoroalkyl group is preferably from 2 to 20, particularly preferably from 6 to 16. If the carbon number of the perfluoroalkyl group is small, water repellency and oil repellency tend to decrease, and if the carbon number of the perfluoroalkyl group is large, handling of (meth)acrylate having the Rf group tends to be difficult.
Specific examples of the Rf group will be given below.
C4F9xe2x80x94 [any one of structurally isomeric groups such as F(CF2)4xe2x80x94, (CF3)2CFCF2xe2x80x94, (CF3)3Cxe2x80x94 and CF3CF2(CF3)CFxe2x80x94], C5F11xe2x80x94 [such as F(CF2)5xe2x80x94], C6F13xe2x80x94 [such as F(CF2)6xe2x80x94], C7F15xe2x80x94 [such as F(CF2)7xe2x80x94], C8F17xe2x80x94 [such as F(CF2)8xe2x80x94], C9F19xe2x80x94 [such as F(CF2)9xe2x80x94], C10F21xe2x80x94 [such as F(CF2)10xe2x80x94], C12F25xe2x80x94 [such as F(CF2)12xe2x80x94], C14F29xe2x80x94 [such as F(CF2)14xe2x80x94], C16F33xe2x80x94 [such as F(CF2)16xe2x80x94], Cl(CF2)sxe2x80x94 (wherein s is an integer of from 2 to 20), H(CF2)txe2x80x94 (wherein t is an integer of from 2 to 20), (CF3)2CF(CF2)yxe2x80x94 (wherein y is an integer of from 1 to 17), etc.
Specific examples of a case where the Rf group is a group having an etheric oxygen atom or a thioetheric sulfur atom inserted between a carbonxe2x80x94carbon bond, will be given below.
F(CF2)5OCF(CF3)xe2x80x94, F[CF(CF3)CF2O]rCF(CF3)CF2CF2xe2x80x94, F[CF(CF3)CF2O]CCF(CF3)xe2x80x94, F[CF(CF3)CF2O]uCF2CF2xe2x80x94, F(CF2CF2CF2O)vCF2CF2xe2x80x94, F(CF2CF2O)wCF2CF2xe2x80x94, F(CF2)5SCF(CF3)xe2x80x94, F[CF(CF3)CF2S]rCF(CF3)CF2CF2xe2x80x94, F[CF(CF3)CF2S]CCF(CF3)xe2x80x94, F[CF(CF3)CF2S]uCF2CF2xe2x80x94, F(CF2CF2CF2S)vCF2CF2xe2x80x94, F(CF2CF2S)wCF2CF2xe2x80x94 (wherein r is an integer of from 1 to 5, u is an integer of from 1 to 6, v is an integer of from 1 to 6, and w is an integer of from 1 to 9), etc.
The water dispersion type water and oil repellent composition of the present invention contains a copolymer (A) as an essential component.
The copolymer (A) is a copolymer containing polymerized units based on a polymerizable monomer having an Rf group (hereinafter referred to as a polymerizable monomer (a1)) and polymerized units based on stearyl (meth)acrylate.
The polymerizable monomer (a1) is preferably a compound wherein the Rf group is located at the alcohol residual portion of (meth)acrylate.
As the polymerizable monomer (a1), preferred is a compound represented by the following formula a11. In the formula a11, Rf represents an Rf group, Q is a bivalent organic group, and R is a hydrogen atom or a methyl group.
Rfxe2x80x94Qxe2x80x94OCOCRxe2x95x90CH2xe2x80x83xe2x80x83Formula a11 
Rf in the formula all is preferably an Rf group containing no etheric oxygen atom or thioetheric sulfur atom, particularly preferably a perfluoroalkyl group, and most preferably perfluoroalkyl group having a linear structure. As the perfluoroalkyl group having a linear structure, a group represented by F(CF2)nxe2x80x94 (wherein n is an integer of from 1 to 20, preferably an integer of from 4 to 16, particularly preferably an integer of from 6 to 12) is preferred.
Q in the formula a11 is preferably xe2x80x94(CH2)p+qxe2x80x94, xe2x80x94(CH2)pCONRa(CH2)qxe2x80x94, xe2x80x94(CH2)pOCONRa(CH2)qxe2x80x94, xe2x80x94(CH2)pSO2NRa(CH2)qxe2x80x94, xe2x80x94(CH2)pNHCONH(CH2)qxe2x80x94, xe2x80x94(CH2)pCH(OH)(CH2)qxe2x80x94, xe2x80x94(CH2)pCH(OCORa)(CH2)qxe2x80x94, etc, wherein Ra is a hydrogen atom or an alkyl group. Further, each of p and q which are independent of each other is an integer of at least 0, and p+q is an integer of from 1 to 22.
Further, Q in the formula a11 is preferably xe2x80x94(CH2)p+qxe2x80x94, xe2x80x94(CH2)pCONRa(CH2)qxe2x80x94 or xe2x80x94(CH2)pSO2NRa(CH2)qxe2x80x94, wherein q is an integer of at least 2 and p+q is from 2 to 6, particularly preferably xe2x80x94(CH2)p+qxe2x80x94 wherein p+q is from 2 to 6 (i.e. ethylene group to hexamethylene group). Further, it is preferred that fluorine atoms are bonded to the carbon atom of Rf which is bonded to Q in formula a11.
The following compounds may be mentioned as specific examples of the polymerizable monomer (a1), wherein in the following compounds, R in the following compounds is a hydrogen atom or a methyl group.
F(CF2)5CH2OCOCRxe2x95x90CH2 
F(CF2)6CH2CH2OCOCRxe2x95x90CH2 
H(CF2)6CH2OCOCRxe2x95x90CH2 
H(CF2)8CH2OCOCRxe2x95x90CH2 
H(CF2)10CH2OCOCRxe2x95x90CH2 
H(CF2)8CH2CH2OCOCRxe2x95x90CH2 
F(CF2)8CH2CH2CH2OCOCRxe2x95x90CH2 
F(CF2)8CH2CH2OCOCRxe2x95x90CH2 
F(CF2)10CH2CH2OCOCRxe2x95x90CH2 
F(CF2)12CH2CH2OCOCRxe2x95x90CH2 
F(CF2)14CH2CH2OCOCRxe2x95x90CH2 
F(CF2)16CH2CH2OCOCRxe2x95x90CH2 
(CF3)2CF(CF2)4CH2CH2OCOCRxe2x95x90CH2 
(CF3)2CF(CF2)6CH2CH2OCOCRxe2x95x90C2 
(CF3)2CF(CF2)8CH2CH2OCOCRxe2x95x90CH2 
F(CF2)8SO2n(C3H7)CH2CH2OCOCRxe2x95x90CH2 
F(CF2)8(CH2)4OCOCRxe2x95x90CH2 
F(CF2)8SO2n(CH3)CH2CH2OCOCRxe2x95x90CH2 
F(CF2)8SO2n(C2H5)CH2CH2OCOCRxe2x95x90CH2 
F(CF2)8CONHCH2CH2OCOCRxe2x95x90CH2 
(CF3)2CF(CF2)5(CH2)3OCOCRxe2x95x90CH2 
(CF3)2CF(CF2)5CH2CH(OCOCH3)OCOCRxe2x95x90CH2 
(CF3)2CF(CF2)5CH2CH(OH)CH2OCOCRxe2x95x90CH2 
(CF3)2CF(CF2)7CH2CH(OH)CH2OCOCRxe2x95x90CH2 
F(CF2)9CH2CH2OCOCRxe2x95x90CH2 
F(CF2)9CONHCH2CH2OCOCRxe2x95x90CH2.
The copolymer (A) may contain one type or at least two types of the polymerized units based on the polymerizable monomer (a1). When the copolymer (A) contains at least two types of the polymerized units based on the polymerizable monomer (a1), at least two types of polymerized units based on (meth)acrylates having Rf groups with different carbon numbers are preferably contained.
As the copolymer (A) of the present invention, it is preferably a copolymer containing one type of polymerized units based on the polymerizable monomer (a1) and polymerized units based on stearyl (meth)acrylate, a copolymer containing at least two types of polymerized units based on the polymerizable monomer (a1) and polymerized units based on stearyl (meth)acrylate, and a copolymer containing at least one type of polymerized units based on the polymerizable monomer (a1), polymerized units based on stearyl (meth)acrylate and at least one type of polymerized units based on another polymerizable monomer (hereinafter referred to as a polymerizable monomer (a2)) (hereinafter referred to as a copolymer (A1)), particularly the copolymer (A1) is preferred. The ratio of the polymerized units based on the polymerizable monomer (a1) in the copolymer (A) is preferably from 50 to 99 mass %, particularly preferably from 55 to 98 mass %, from the viewpoint of water and oil repellency. In the copolymer (A1), the ratio of the polymerized units based on the polymerizable monomer (a1) is preferably from 50 to 99 mass %, particularly preferably from 55 to 98 mass %, from the viewpoint of water and oil repellency, and the ratio of polymerized units based on stearyl (meth)acrylate is preferably from 1 to 50 mass %, particularly preferably from 2 to 45 mass %.
Stearyl (meth)acrylate may be stearyl acrylate alone, stearyl methacrylate alone or a combination thereof.
As the polymerizable monomer (a2), it is preferred that a polymerizable monomer has one or two polymerizable unsaturated groups, particularly it is preferred that a polymerizable monomer has one polymerizable unsaturated group. Further, the copolymer (A1), may contain one type or at least two types of polymerized units based on the polymerizable monomer (a2).
The copolymer (A1) preferably contains at least one type of the polymerized units based on the polymerizable monomer (a2) the polymerizable monomer (a2) is preferably at least one member selected from the following polymerizable monomers.
The polymerizable monomer (a2) may be an olefin, vinyl carboxylate, styrene, a substituted styrene, (meth)acrylamide, an N-substituted (meth)acrylamide, an alkyl vinyl ether, a (substituted alkyl) vinyl ether, a vinyl alkyl ketone, a diene, glycidyl (meth)acrylate, aziridinyl (meth)acrylate, a substituted alkyl (meth)acrylate, a hydroxyalkyl (meth)acrylate, a hydroxyl group terminal polyoxyalkylene (meth)acrylate, an alkoxy group terminal polyoxyalkylene (meth)acrylate, a polyoxyalkylene di(meth)acrylate, a polysiloxane group-containing (meth)acrylate, triallyl cyanurate, allyl glycidyl ether, allyl carboxylate, N-vinyl carbazole, N-methylmaleimide, maleic anhydride, a maleic monoalkyl ester, a maleic dialkyl ester or a blocked isocyanurate group-containing (meth)acrylic ester.
Further, the polymerizable monomer (a2) may, for example, be preferably vinyl acetate, styrene, xcex1-methylstyrene, p-methylstyrene, glycidyl (meth)acrylate, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, diacetone (meth)acrylamide, methylol diacetone (meth)acrylamide, N-methylol (meth)acrylamide, a vinyl alkyl ether, a halogenated alkyl vinyl ether, a vinyl alkyl ketone, aziridinyl ethyl (meth)acrylate, benzyl (meth)acrylate, aziridinyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, a polyoxyalkylene (meth)acrylate, a methylpolyoxyalkylene (meth)acrylate, 2-ethylhexylpolyoxyalkylene (meth)acrylate, a polyoxyalkylene di(meth)acrylate, (meth)acrylate having polysiloxane, triallyl cyanurate, allyl glycidyl ether, allyl acetate, 2-hydroxy-3-chloropropyl (meth)acrylate, N-vinylcarbazole, maleimide, N-methylmaleimide or (2-dimethylamino)ethyl (meth)acrylate.
In the present invention, the copolymer (A) is preferably dispersed as particles in the composition. The average particle diameter of the particles is preferably from 10 to 1,000 nm, more preferably from 10 to 300 nm, particularly preferably from 10 to 200 nm. Further, with respect to the particles of the copolymer (A), the ratio of particles having an average particle diameter of from 30 to 150 nm is preferably at least 80%, more preferably at least 90%, particularly preferably at least 95%, of the total number of particles. If the average particle diameter is smaller, it may be necessary to add a large amount of surfactants in order to improve stability of the composition, thus it causes a decrease in water and oil repellency or color fading of a treated object. On the contrary, when the average particle diameter is too large, there is fear that the copolymer (A) may precipitate.
The average particle diameter can be measured by e.g. a dynamic light scattering apparatus, an electron microscope or capillary hydrodynamic fluctuation (hereinafter referred to as CHDF). When polymerization is carried out in the presence of a surfactant by a conventional emulsion polymerization method as mentioned hereinafter, the average particle diameter is within the above range.
With respect to stearyl (meth)acrylate to be used in the present invention, the concentration of the impurity (B) derived from the material of it is at most 9 mass %, preferably at most 6 mass %, particularly preferably at most 4 mass %, in the material stearyl (meth)acrylate as the raw material.
When the concentration of the impurity (B) exceeds 9 mass %, the uniform mixing properties of the polymerizable monomer (a1) with stearyl (meth)acrylate tend to become worse, the fluctuation of the copolymer composition of the copolymer (A) tends to be significant, and e.g. storage stability and water and oil repellency of the water and oil repellent composition tend to become worse.
The reason why the uniform mixing properties become worse is not clearly understood, but it is considered that a thermodynamic balance in the prepolymerization fluid is disturbed by the presence of an impurity, and formation of uniform monomer oil droplets before the polymerization reaction is inhibited. It is considered that, as a result, no copolymer having a uniform composition can be produced, and water and oil repellency decreases or particles precipitate due to formation of particles having a heavy specific gravity.
As an analysis method of stearyl (meth)acrylate, capillary gas chromatography may be employed. It is considered that three types of impurities such as stearyl alcohol, the impurity X and the impurity Y which are determined by the following analytical method have a particularly bad influence on polymerization. Especially the impurity Y has bad influence.
Analytical method: Capillary gas chromatography
Analytical conditions: Capillary column tube; DB-5HT (30 mxc3x97film thickness 0.1 xcexcm), injection temperature; 300xc2x0 C., detector temperature; 380xc2x0 C., gas flow rate; 25 psi, split ratio; 100 to 1, amount of sample injected; 0.5 xcexcl, sample solution; 10 mass % chloroform solution, temperature of column oven; held at 40xc2x0 C. for 1 minute, then increased to 170xc2x0 C. at a rate of 20xc2x0 C. per minute, held at 170xc2x0 C. for 5 minutes, and then increased to 380xc2x0 C. at a rate of 20xc2x0 C. per minute, and held at 380xc2x0 C. for 5 minutes.
Further, because stearyl alcohol reacts with stearyl (meth)acrylate with time passing to form the impurity Y, so it is necessary to pay attention to the content of stearyl alcohol in stearyl (meth)acrylate.
Among these three impurities, the stearyl alcohol is considered to be an unreacted material in synthesis of stearyl (meth)acrylate, and the impurities X and Y are considered to be by-products formed due to inappropriate reaction conditions in synthesis of stearyl (meth)acrylate.
Examples of the impurity X include the following compounds.
H(CH2)18OCO(CH2)2OCOCHxe2x95x90CH2 
H(CH2)18OCO(CH2)2OCOC(CH3)xe2x95x90CH2 
H(CH2)18OOCH2CH2OCOCHxe2x95x90CH2 
H(CH2)18OCOCH2CH(CH3)OCOC(CH3)xe2x95x90CH2 
Examples of the impurity Y include the following compounds.
H(CH2)18OCO(CH2)2O(CH2)18H
H(CH2)18OCOCH2CH(CH3)O(CH2)18H
As a method for removing these impurities, a method of removing them by purification such as distillation or recrystallization after synthesis of stearyl (meth)acrylate, or a method of optimizing reaction conditions of the synthesis of stearyl (meth)acrylate to increase the conversion of stearyl alcohol with controlling the stearyl alcohol not to react with (meth)acrylic acid or stearyl (meth)acrylate, may be considered.
In either method, the amount of stearyl alcohol is at most 3 mass %, particularly preferably at most 1 mass %, of the stearyl (meth)acrylate. Further, the amount of the impurity X is preferably at most 2 mass %, particularly preferably at most 1 mass %, of the stearyl (meth)acrylate. Further, the amount of the impurity Y is preferably at most 4 mass %, particularly preferably at most 2.5 mass %, of the stearyl (meth)acrylate. Particularly, the total amount of three impurities stearyl alcohol, impurity X and impurity Y is at most 4 mass % of the stearyl (meth)acrylate.
The stearyl (meth)acrylate to be used in the present invention has a purity of preferably higher than 91 mass %, particularly preferably from 94 to 100 mass %, most preferably from 96 to 100 mass %, as analyzed by the above-described capillary gas chromatography.
The method for producing the copolymer (A) of the present invention is not particularly limited. Preferably, the polymerizable monomer having an Rf group and stearyl (meth)acrylate are polymerized in an aqueous medium by a well known method such as an emulsion polymerization or a dispersion polymerization. In a case of polymerization by an emulsion polymerization method or a dispersion polymerization method, it may be mentioned that, for example, an initiator is added in the presence of a surfactant and a polymerization medium. As the surfactant, at least one of nonionic, cationic, anionic and amphoteric surfactants may be employed. The amount of the surfactant is preferably from 0.5 to 20 parts by mass based on 100 parts by mass of the copolymer (A), preferably from 1 to 15 parts by mass from the viewpoint of water and oil repellency and dispersion stability, particularly preferably from 5 to 12 parts by mass.
Specific examples of the surfactant will be given below, but the surfactant is not limited thereto. Further, in the following examples of the surfactant, the alkyl group portion such as an octadecyl group may be an alkenyl group portion such as an oleyl group.
The nonionic surfactant may, for example, be an alkylphenyl polyoxyethylene, an alkylpolyoxyethylene, an alkylpolyoxyalkylene polyoxyethylene, a fatty acid ester, an alkylamine oxyethylene addition product, an alkanoic amide oxyethylene addition product, an alkylamine oxyethylene oxypropylene addition product, an alkylamine oxide, or a compound having a carbonxe2x80x94carbon triple bond and a hydroxyl group in its molecule (specific examples: e.g. Surfynol 420, Surfynol 465, Surfynol 485, etc., manufactured by NISSIN CHEMICAL INDUSTRY CO., LTD.).
The alkylphenyl polyoxyethylene may, for example, be nonylphenyl polyoxyethylene or octylphenyl polyoxyethylene.
The alkyl portion in the alkylpolyoxyethylene may be a linear or branched saturated fatty acid group having a carbon number of from 4 to 26, and specific examples thereof include an octyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, a behenyl group and a secondary alkyl group.
The alkylpolyoxyalkylene polyoxyethylene may, for example, be alkylpolyoxypropylene polyoxyethylene or alkylpolyoxybutylene polyoxyethylene, and the alkyl portion may be the same alkyl portion as mentioned above.
The cationic surfactant may, for example, be an amine salt, a quaternary ammonium salt or an oxyethylene addition type ammonium salt, and specific examples thereof include an alkyldimethylamine hydrochloride, a dialkylmethylamine hydrochloride, an alkyltrimethylammonium chloride, a dialkyldimethylammonium chloride, a monoalkylamine acetate and an alkylmethyldipolyoxyethylene ammonium chloride. The alkyl portion may be the same alkyl portion as mentioned above.
The anionic surfactant may, for example, be a fatty acid salt, an xcex1-olefin sulfonate, an alkylbenzene sulfonate or its salt, an alkylsulfate, an alkyl ether sulfate, an alkyl phenyl ether sulfate, an N-acylmethyl taurine salt or an alkylsulfosuccinate.
The amphoteric surfactant may, for example, be an alanine, an imidazolinium betaine, an amidebetaine, or acetic betaine, and specific examples thereof include lauryl betaine, stearyl betaine, laurylcarboxymethylhydroxyethyl imidazolinium betaine, lauryldimethylamino acetic betaine and fatty acid amidepropyldimethylamino acetic betaine.
The polymerization medium is preferably an aqueous medium containing water, and an organic solvent may be contained in the aqueous medium as the case requires. As the organic solvent, a water-soluble organic solvent is preferred, and an organic solvent such as an ester type, a ketone type or an ether type is preferred. The ratio of water to the organic solvent is not particularly limited.
Specific examples of the organic solvent include acetone, ethylene glycol monoethyl ether monoacetate, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether monoacetate, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol dibutyl ether, ethyl 3-ethoxypropionate, 3-methoxy-3-methyl-1-butanol, 2-t-butoxyethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, ethyl alcohol, ethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and tetrapropylene glycol.
As the polymerization initiator, a water-soluble or oil-soluble polymerization initiator may be used, and a general purpose initiator of e.g. an azo type, a peroxide type or a redox type may be used depending upon the polymerization temperature. The polymerization initiator is preferably a water-soluble initiator, particularly preferably a salt of an azo type compound.
The polymerization temperature is not particularly limited, but is preferably from 20 to 150xc2x0 C.
In the polymerization reaction of the polymerizable monomer, a chain transfer agent may be incorporated with a purpose of controlling the molecular weight. The chain transfer agent is preferably an aromatic compound or a mercaptan, particularly preferably an alkyl mercaptan. As specific examples of the chain transfer agent, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, stearyl mercaptan and a-methylstyrene diner CH2xe2x95x90CPhCH2C(CH3)2Ph [Ph is a phenyl group], may be preferably mentioned.
As a preliminary step to initiation of the polymerization, a mixture comprising the polymerizable monomer, the surfactant and the aqueous medium may be preliminarily dispersed by a homomixer or a high pressure emulsifier. By agitating the mixture well before initiation of the polymerization, such effects can be obtained that the yield of the polymer to be obtained finally is improved, and the fluctuation width of the average particle diameter of the polymer particles can be narrowed.
The surfactant may be added at the time of the emulsion polymerization and/or after the emulsion polymerization.
The water dispersion type water and oil repellent composition of the present invention is a composition having the copolymer (A) dispersed in an aqueous medium. The composition may be prepared by dispersing the copolymer (A) in a desired aqueous medium, but usually, a desired medium is employed as the polymerization medium in the polymerization reaction to directly prepare the water dispersion type water and oil repellent composition.
The aqueous medium is preferably water or a medium containing water and an organic solvent. The organic solvent may be one similar to the organic solvents as disclosed as the polymerization medium in the above method for producing the copolymer (A). The content of the organic solvent is preferably at most 40 mass % based on the weight of the copolymer (A).
The amount of the copolymer (A) is preferably from 1 to 50 mass % based on the aqueous medium, but the concentration may optionally be changed depending upon the purpose of use or the preparation mode of the composition.
The water dispersion type water and oil repellent composition of the present invention is excellent in water and oil repellency, and it is thereby useful as a water dispersion for water and oil repellent. The water dispersion may be diluted to an optional concentration depending upon the particular purpose or application and then applied to an object to be treated. The application method to an object to be treated may also be optional depending upon the type of the object to be treated, the formulation of the composition, etc. For example, a method may be mentioned wherein it is deposited on the surface of the object to be treated by a covering method such as dip coating, followed by drying. Further, if necessary, it may be applied together with a suitable crosslinking agent, and curing may be carried out.
The water dispersion type water and oil repellent composition of the present invention exhibits excellent stability and excellent durability in water and oil repellency, even if it is used together with another compound, and accordingly an additive such as another polymer blender, another water repellent, an oil repellent, an insecticide, a flame retardant, an antistatic agent, a dye stabilizer or an anticrease agent may be used together as the case requires.
The water dispersion type water and oil repellent composition of the present invention may be applied to an object to be treated at an optional concentration. For treatment of the object to be treated, dipping is preferred, and further, it is preferred to carry out drying. Further, curing may be carried out as the case requires. The dipping time is preferably from 1 to 10 seconds, and the time may optionally be changed depending upon the object to be treated.
The object to be treated with the water dispersion type water and oil repellent composition of the present invention is not particularly limited, and it may, for example, be fiber fabrics, glass, paper, wood, leather, fur, asbestos, brick, cement, a metal or its oxide, a ceramic, a sealing agent or a plastic, and preferred are fiber fabrics and paper.
The fibers or fiber fabrics may, for example, be animal or plant natural fibers such as cotton, hemp, wool and silk, synthetic fibers such as polyamide, polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride and polypropylene, semisynthetic fibers such as rayon and acetate, inorganic fibers such as glass fibers, carbon fibers and asbestos fibers, and fabrics of mixed fibers thereof.
Now, the present invention will be explained in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples.
The average particle diameter in Examples were measured by means of a CHDF method (xe2x80x9cCHDF2000xe2x80x9d manufactured by MATEC SCIENCE). As a high pressure emulsifier, a high pressure homogenizer manufactured by Manton-Gaulin was employed.
Further, symbols in Examples have the following meanings.
FA: F(CF2)mCH2CH2COCHxe2x95x90CH2 (a mixture of compounds wherein m is 6, 8, 10, 12, 14 and 16, and the average of m is 9)
StA: Stearyl acrylate
NMAM: N-methylolacrylamide
DOM: Dioctyl maleate
HEA: Hydroxyethyl acrylate
DPG: Dipropylene glycol
PEOOE: (Polyoxyethylene)oleyl ether
StTMAC: Stearyl trimethylammonium chloride
PEONPE: Polyoxyethylene mono(nonylphenyl) ether
HDEO: Polyoxyethylene mono(hexadecyl) ether
PEOLE: Polyoxyethylene mono (2-dodecyl) ether,
StSH: Stearylmercaptan
DOSH: n-Dodecylmercaptan